This application claims priority from Japanese application 2000-138958 filed May 11, 2000, and Japanese application 2000-157293 filed May 26, 2000, which are hereby incorporated by reference into this application.
1. Field of the Invention
The present invention relates to a head protection air bag apparatus mounted in a vehicle. The head protection air bag apparatus is provided with a folded air bag in a predetermined location on the interior side of a vehicle.
2. Description of the Related Art
Conventionally, in this kind of head protection air bag apparatus, an air bag is folded to be housed on an upper edge side of the periphery of an opening on the interior or inner side of a vehicle, that is, in a periphery from a front pillar portion to a roof side rail portion, as described in the Japanese Laid-Open Patent Application No. Hei 11-321532.
A gas for inflation supplied by an inflator flows into the air bag from either its front end side or rear end side. Accordingly, it takes a long time for the gas for inflation to reach the terminal end of the air bag, which is located away from the inflator.
The length of the air bag should be long in a front-rear direction when the air bag is mounted on a vehicle, in vehicles which include several rows of seats for passengers. In this case, it takes a long time for the gas for inflation to reach the air bag terminal end.
In order to solve this problem, it can be considered to shorten the distance between the inflator and the terminal end in a front-rear direction of the air bag, as described in WO 96/26087. In WO 96/26087, the inflator is disposed on the upper edge side of a periphery of an opening on the inner side of a vehicle between the front pillar portion and the rear pillar portion, that is, in the roof side rail portion.
The inflator is made of a metal having high rigidity. Thus, taking impacts between the inflator and a passenger into account, a cover material for covering the inflator to function as a cushion is separately required when disposing the inflator in the roof side rail portion. Preparing the cover material, however, increases the number of components of the air bag as well as the number of processes for installing the air bag apparatus in a vehicle.
In a conventional head protection air bag apparatus, the air bag is folded to be housed on an upper edge side of a periphery of an opening on the inner side of a vehicle so as to extend from the front pillar portion to the rear side passing over the center pillar portion, as described in the Japanese Laid-Open Patent Application No. Hei 10-138858.
The air bag in the above Japanese Laid-Open Patent Application No. Hei 10-138858 is in a folded shape and covered by a door portion of an air bag cover at a location of a roof side rail portion on an upper edge side of an opening on the inner side of a vehicle. The door portion is disposed on a lower edge side of a roof head lining. The air bag, which has been developed and inflated, pushes and opens the door portion of the air bag cover. The air bag is developed and inflated so as to cover the inner side of a vehicle of a center pillar garnish at a location of the center pillar portion. The center pillar garnish is disposed on the inner side of a vehicle of the center pillar portion.
In the conventional head protection air bag apparatus, however, a lower edge portion of the air bag cover door portion is connected to the upper edge portion of the pillar garnish of the center pillar portion. The lower edge portion of the cover door portion includes a curved portion toward the exterior, or the outer side, of a vehicle. Thus, the door portion must climb over the upper edge portion of the pillar garnish to be opened when the air bag pushes and opens the door portion. As a result, in the conventional head protection air bag apparatus, the door portion is difficult to open smoothly and thereby, there is a need for improving the quick development and inflation of the air bag.
One aspect of the invention is to provide a head protection air bag apparatus capable of covering an inflator without increasing the number of components with a cushion characteristic when the inflator is disposed in a roof side rail portion or the like.
Another aspect of the invention is to provide a head protection air bag apparatus in which an opening operation of a lower edge portion of an air bag cover, which abuts an upper edge portion of a pillar garnish, is made free of restriction so that development and inflation of the air bag can be completed quickly.
The first aspect of the invention can be achieved by a head protection air bag apparatus having a following structure. This head protection air bag apparatus comprises an air bag, an air bag cover for covering the air bag, an inflator for supplying the above air bag with a gas for inflation, fixing elements for fixing the inflator to a body of the vehicle, and an assist grip. The air bag is covered by the air bag cover. The air bag is folded and housed on the exterior side of the vehicle, relative to the air bag cover, and the gas for inflation from the inflator is emitted into the air bag so that the air bag pushes and opens the air bag cover as the air bag is developed and inflated. The inflator is disposed at a location toward the exterior, or outer side, of the vehicle body relative to the assist grip when fixed to the vehicle body.
In the head protection air bag apparatus according to an embodiment of the invention, the assist grip is used as a cover material of the inflator. The assist grip, which is properly provided with a core material made of a metal, is provided on its surface side with a cushioning cover layer made of a soft synthetic resin such as soft vinyl chloride and urethane.
Therefore, a passenger will impact the assist grip, which has the characteristic of a cushion, in situations when the passenger would impact the inflator. As a result, the impact of the passenger is less injurious than an impact in situations when no assist grip is provided.
The assist grip itself is a component mounted in the roof side rail portion or the like of a vehicle. Thus, the use of the assist grip in the head protection air bag apparatus does not increase the number of components mounted in a vehicle.
Therefore, in the head protection air bag apparatus according to this embodiment of the invention, the inflator can be covered without increasing the number of components. The inflator is covered with an assist grip having the characteristic of a cushion even when the inflator is disposed in the roof side rail portion.
A condition of a location of the inflator disposed toward the outer, or exterior side of a vehicle of the assist grip is that a passenger does not impact the inflator such as would occur in situations where only the air bag cover exists in between the passenger and the inflator. Accordingly, the inflator may be disposed either toward the exterior side of a vehicle in a horizontal direction of the assist grip, or also toward the exterior side of a vehicle in an obliquely upper or lower direction relative to the assist grip.
In this head protection air bag apparatus, it is desirable that the inflator and the assist grip are fixed to the vehicle body by means of common fixing elements.
In this arrangement, the inflator and the assist grip are fastened together to be fixed to the body by means of the common fixing elements. In such an arrangement, the numbers of components and installation processes in installing the inflator and the assist grip in the body is decreased.
Further, the inflator, the assist grip and the air bag cover may be fixed to the body by means of the common fixing elements. In this arrangement, the air bag cover is also fastened together with the inflator and the assist grip to be fixed to the body. In such arrangement, the numbers of components and installation processes in installing the inflator, the assist grip, and the air bag cover in the body can be decreased.
Moreover, in the first head protection air bag apparatus, a unitary air bag installation body may be formed. This air bag installation body is the assist grip, the air bag, the inflator, and the air bag cover are coupled together into a unitary body to be installed into the vehicle body. In such an arrangement, the air bag apparatus is installed within the vehicle body through the installation of the installation body. As a result, the installation operation required for installing the air bag apparatus in a vehicle is be improved.
A decorative or functional design characteristics of the inner side of a vehicle would not be decreased when interior decoration of the roof side rail garnish and the roof head lining is used for forming the air bag cover.
The second aspect of the invention is achieved by a head protection air bag apparatus having a following structure. This head protection air bag apparatus comprises an air bag and an air bag cover. The air bag is folded and housed at an upper location of a pillar portion on the interior, or inner, side of the vehicle body. The air bag covers a pillar garnish disposed on the interior side of the pillar portion when developing and inflating. The air bag cover is configured to move between a closed and an open position. In the closed position, the cover covers the folded air bag and is opened when pushed by the developed and inflated air bag. A lower edge portion of the air bag cover is disposed toward the vehicle interior relative to an upper edge portion of the pillar garnish, and is abutted to the pillar garnish.
In the second head protection air bag apparatus according to the invention, a lower portion of the air bag can immediately open and move to the inner side of a vehicle without climbing over the upper edge portion of the pillar garnish when the developed and inflated air bag pushes the air bag cover.
Accordingly, in the second head protection air bag apparatus according to the invention, an opening operation of the lower edge portion of the air bag cover to be connected to the upper edge portion of the pillar garnish would be smooth, so that development and inflation of the air bag can be completed quickly.
In the second head protection air bag apparatus, it is desirable that, when the pillar garnish is provided with a general portion disposed below the upper edge portion of the garnish, the lower edge portion of the air bag cover is abutted to the pillar garnish in a manner so as to be in a same plane with the general portion of the pillar garnish. In such an arrangement, the decorative and functional design characteristics of the air bag cover and the pillar garnish do not decrease.
Further, in the second head protection air bag apparatus, it is desirable that, in situation when the vehicle comprises a front pillar portion, a rear pillar portion and a middle pillar portion between the front pillar portion and the rear pillar portion, the air bag cover is provided on the inner side of the vehicle and extends from the front pillar portion to the rear pillar portion as one integrated body. In such an arrangement, the air bag cover continuously covers roughly the entire upper edge side of a periphery of an opening on the inner side of a vehicle. Thus, the decorative and functional design characteristics of the inner side of a vehicle are improved compared with situations when the air bag cover is disposed in parts on the inner side of a vehicle.
In the second embodiment of the head protection air bag apparatus, an air bag installation body is also formed. This air bag installation body is the air bag and the air bag cover coupled together for installation in a vehicle body as a unitary body. In such an arrangement, the air bag apparatus is installed within the vehicle body through the installation of the installation body. As a result, the installation operation required for installing the air bag apparatus in a vehicle is improved.
Moreover, in the second head protection air bag apparatus, the upper edge portion of the pillar garnish may be connected to the body so as to fill a space between the pillar garnish and the body. In such an arrangement, the upper edge portion of the pillar garnish prevents the air bag from entering between the pillar garnish and the body when the air bag is developed and inflated, so that the air bag is directed to the lower edge portion side of the air bag cover. Accordingly, the air bag can be smoothly projected to the inner side of a vehicle.
In the above arrangement, the air bag cover comprises a door portion, to be opened when pushed by the air bag, and a general portion disposed above the door portion. It is desirable that the general portion of the air bag is provided with a lateral wall portion for filling a space between the general portion of the air bag and the body. The lateral wall is disposed above the location between the pillar garnish and the vehicle body where the folded air bag is disposed. In such an arrangement, the lateral wall portion can prevent the air bag from entering between the general portion of the air bag cover and the vehicle body, when the air bag is developed and inflated. Accordingly, the air bag is directed to the door portion of the air bag cover. Thus, the air bag smoothly projects to the inner side of a vehicle.
In the second head protection air bag apparatus, it is arranged that the upper edge portion of the air bag cover covers the interior side of a lower edge portion of the roof head lining that is disposed above the air bag cover. That is, the upper edge portion of the air bag cover is disposed on the interior side of the vehicle, relative to the lower edge portion of the roof head lining, and abutted to the roof head lining. In such an arrangement, the roof head lining can be mounted in a vehicle even when a terminal treatment such as trimming of the roof head lining lower edge portion is insufficient. This is because the upper edge portion of the air bag cover covers the roof head lining lower edge portion. As a result, the terminal treatment of the roof head lining lower edge portion can be easily performed through this design. A decrease of the appearance of the roof head lining can also be controlled.